Most animals obtain food from hunting or foraging. Rarely, some, like the ant, also produce food through farming. Some species of ants raise aphids to eat the honeydew the smaller insects produce.
Nearly all animals are heterotrophs, meaning that they eat other organisms to survive. Carnivores are animals that only eat other animals for food. For instance, a lioness is a carnivore and gets food through hunting prey animals. Herbivores are animals that eat plants as food. A cow is an herbivore that eats only grasses, hay, oats and other plants for nutrients. The omnivore is an animal that eats both animals and plants for food. Among omnivores are bears, pigs, squirrels and humans.
Animals evolve to make the most of the food sources that are available in their natural environment. In fact, natural selection can cause a species to change in shape, size, intellect and habit to make it better able to hunt or forage for food in that environment. Humans have adapted to successfully obtain food from a wide range of environments, and humans have developed farming and animal husbandry to grow food as needed. Other animals are specially adapted to eat only one type of food. One example is the Giant Panda, which only eats bamboo.